Process for packaging meat products and article produced thereby



Jan. 1, 1957 c. J. s. THOMAS 2,776,216

PROCESS FOR PACKAGING MEAT PRODUCTS AND ARTICLE PRODUCED THEREBY FiledApril 3-, 1951 FI G. 3.

t! is n- FIG.5.

INVENTOR. 60;; J. 5. TH ME ATTORNEY Patented Jen. ll, $.95?

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PROCESS FOR PACKAGlNG MEAT PRODUCTS AND ARTICLE PRODUCED THEREBY ColinJ. S. Thomas, Ruxton, Md.

Application April 3, 1951, Serial No. 219,063

17 Claims. (Cl. 99-474) This invention relates to the packaging orWrapping of meat products and especially to novel. means for preservinga predetermined contour of a part or all of such a product, such as thecontour of a fish, and to eliminate or diminish to a minimum air spacesin and around the product within the wrapping.

Heretofore meat products such as hams and bacon have been enclosed inwrappings of textile woven material which are drawn tightly around thearticles and stitched. This kind of a wrapping is solely for protection.It does not permit of visual inspection of the wrapped material withoutdestroying the covering. It does not tend to preserve any given shape tothe wrapped article, and it provides little or no protection from oxygenof the atmosphere. Dressed fowl has been wrapped for freezing in atransparent or translucent sheet material which is drawn or shrunktightly about the fowl. This kind of a wrapping is a desirable enclosurefor'materials of irregular and massive contour, the shapes of which arenot material as a matter of sales display. The wrapping is not entirelysatisfactory however, where the material is frozen for the reason thatquite large cavities remain in the Wrapped fowl and considerable wateris present in the cavities which collects upon the inside of thewrapping on freezing. This kind of a wrapping modified by completelyfilling the cavity in a fowl with frozen water adds little, if any,improvement over a cavity which is only partially filled with frozenwater. The presence of added water practically prevents accurateWeighing of the packaged fowl. None of these wrappings, however, issatisfactory for wrapping a meat product which has a predeterminedcharacteristic shape such as a fish, wherein it is material to preserveintact an easily deformable feature of the product such as a fin or tailstructure and where the wrapped material does not have a non-deformableskeleton structure which prevents distortion when the wrapping materialis tightly stretched or shrunk around the material. The Wrappingsheretofore used do not materially exelude atmospheric air from cavitieswithin the wrapping.

It is among the objects of this invention to providea wrapping whichentirely eliminates or diminishes internal cavities of the wrappedmaterial so that little or no atmospheric air will remain in thepackage, thus materially improving the preservative qualities of thewrapping. Another object is to provide a wrapping which excludes allmaterial amounts of atmospheric air from between the wrapped materialand the wrapping. Another object is to provide a wrapping which permitsthe shape and color of the wrapped material to be displayed and readilyinspected. A still further object is to provide a planar or flat baseupon which the wrapped material is supported and about which the outerwrapping. is shrunk and to exclude air from the wrapping. Still otherobjects of the invention will be apparent from the following moredetailed description thereof.

I have found a combination of materials and a method of mounting andwrapping such articles which provides packaged meat products inexcellent form for packing in refrigerated spaces, and further providesa protective covering closely conforming to the shape of the wrappedmaterial. The Wrapping is sufficiently transparent to faithfully displaythe exterior color and easily distortable physical features of thewrapped material. The finished package may be caused to be shaped so asto faithfully display desired characteristic lines of the article andprovide an article of distinctive appearance. For example, a fish or apair of fish are wrapped in accordance with the present invention sothat the finished package simulates the characteristic appearance of afish and the easily dist-ortable parts of individual fish such as thetail fin are faithfully preserved while still providing a protectivewrapping stretched over and around the distortable part and excludingair pockets from within the wrapping. The packaging means comprises arelatively stifi base material which is enclosed within the outsidewrapping and this wrapping conforms to the base element as well as toall the exposed surface of the wrapped material so that air bubbles areexcluded and frost forming receptacles are excluded from the outersurface of the base material. This is a considerable advantage since thedeteriorating effect of the air is excluded from this part of thepackage. The exposed surface of the base material reverse to the surfacewhich is in contact with the wrapped material is rendered visible, sothat printing or identification marks may be readily seen through atransparent wrapping.

The invention will be more fully described with reference to theaccompanying drawings which show an illustrative embodiment of theinvention, in which:

Fig. l is a top plan view of a fish wrapped in accordance with thepresent invention.

Fig. 2 is a cross-sectional view of the article shown in Fig. 1, takenalong the line 2-2 of Fig. 1.

Fig.- 3 is a top plan view of a pair of fish mounted back to back'andwrapped in accordance with the present in vention.

Fig. 4 is a cross sectional view of the package shown in Fig. 3, takenalong the line 4-4 of Fig. 3.

Fig. 5 is an enlargement of a portion of Fig. 4 showing the closedcollapsed cavity of a fish from which the viscera have been removed, andthe disposition of the Wrapped material and Wrapping at the edge of thebase material.

In general, the various parts of the wrapping comprise an enclosingsheet-like covering, preferably of a transparent or translucentfilamentous material. The material is of a kind which is imperforate toair and vapor, pliable, relatively strong, and which upon being heatedor immersed in hot water will shrink, and when heated to suchtemperature and tightly shrunk around a wrapped object will remainsufficiently strong not to rupture. Referring to Figs. l to 5 of thedrawings the easily deformable material 2 to be wrapped, such as adressed fish, is laid on a formed, relatively difficultly deformablesheet-like base element 3 which is shaped to conform generally to alongitudinal cross-sectional shape of the article to be wrapped, such asa fish. The shape of the base element is preferably but not necessarilymade smaller in one or more dimension than the maximum longitudinalcrosssection of the article to be wrapped in order to provide forcompressing the article when the wrapping material is shrunk around thearticle. The base element should be shaped and limited in area so thatthe material of the article to be wrapped will be distorted to the veryedge of the base element "when the wrapping is shrunk and so that no airspace will remain around this margin. The base element may be formedfrom a relatively thin material such as a relatively stiff papercardboard, but other materials having the' desired properties can beused. In the case of a wrapping for an eviscerated fish such as thatshown in the drawings, a cardboard of desired thickness and stiffness iscut out generally like a longitudinal cross-section of the fish to bewrapped and of a size such that when the wrapping material is shrunkaround the article, tne tail fin will coincide with the shaped tailportion of the base material and the meaty portions of the fish will bedistorted to conform to the surface of the base material throughout, andso that the meaty portions of the article will meet smoothly at themargins of the base material and the margins of the cavities within thefish will be drawn together and close the cavities.

A suitable sheet wrapping material for this purpose is a vinylvinylidene chloride copolymer which is transparent or only slightlytranslucent. It is economical to form the sheet material into a bag buta plain sheet of material may be used instead of a bag. A single fishsuch as that shown in Fig. 1 may be laid on the base element 3 andinserted in a bag made of the above named plastic sheet material. Theair in the bag is then exhausted sufiiciently to partially or whollycollapse any cavities within the eviscerated fish and to cause the bagto collapse and conform to any surface cavities or external undulationsof the article. In this form the plastic sheet is somewhat wrinkled anddeformed in numerous different directions. The mouth of the bag orwrapping is then suitably sealed as by twisting together the projectingportions which may be tied with a string or stapled as shown in Figs. 1and 3. The article thus wrapped is then heated in order to shrink thesheet material. The wrapping is heated to a temperature which causes thewrapping to shrink. It is convenient to immerse the entire wrappedarticle in hot water which is heated to a temperature sutficient tocause extensive shrinking of the plastic bag, say to about 70% of itsoriginal size. The temperature may be regulated according to theshrinking characteristics of the kind of material used for the wrapping.A temperature of about 90 C. is suitable for shrinking the above namedpolymer, but higher or lower temperatures may be used. This shrinkagecauses the wrapping material to be tightly and smoothly drawn around theexposed surfaces of the wrapped material and base element and tocompress the meaty material within the wrapping and against the baseelement. The bag or wrapping is made of suitable snugness to distort themeaty parts of the wrapped material when the wrapping is shrunk, and sothat the edges 4 of the base element 3 will conform smoothly to thedistorted confined margins 5 of the wrapped material when the width ofthe base material is narrow as shown in Fig. 5, and the shrinking of thesheet material 3, collapses the meaty article more or less according tothe amount of exhaustion and the amount of shrinkage applied, and themeat and base element conform to each other. There will remain either nocavity or only a diminished cavity 6 within the packaged material. Theexhaustion of air tends to collapse the cavity 6 within the material.The exhaustion together with the shrinkage of the wrapping, completelycloses the outer margins of the cavity. This results in a partial or atotal collapsing of any cavity in the wrapped material so that all airis excluded from such internal cavities 6 or all but immaterial amountsare excluded. Spaces and air pockets are also eliminated from betweenthe sheet material and depressions in the surface of the wrappedmaterial. Further, the outer edges of the cavity are securely closed bythe shrinkage of the wrapping so that upon freezing, any frost which mayresult from the freezing of moisture within the package is obscuredwithin the closed cavity. At the same time, the shrinking of thewrapping material conforms exactly to the outer surfaces of the fish andbase material so that all the cavities wherein frost or frozen watermight accumulate are closed or obscured from view. It is evident thatall cavities may be completely collapsed and eliminated by the exerciseof care, but partial collapsing of such cavities is effective providedthe margins of the cavities are drawn together.

In assembling two fish as shown in Figs. 3 and 4, the

base material 3 is preferably cut out so that the fish can be assembledback-to-back. At the tail end, the base material is shaped similar tothat of a fish and so that the terminus of the tail fin of one of thefish will cover somewhat more than half of the tail portion of the basematerial. In length the base material is cut out about the length of thefish to be packaged, but the width is preferably made somewhat narrowerthan the maximum width of two fish laid back to back and upon theirsides. This provides for considerable distortion of the more easilydistortable meaty portions of the fish when air exhaustion and shrinkageof the sheet material are applied. The first fish is laid on the basematerial with one edge of the tail fin coinciding with one edge of thetail fin portion of the base material as shown in Fig. 3. Then thesecond fish is laid on the base material back-to-back to the first fishand with its tail overlapping that of the first fish and with thenon-overlapping portion of its tail conforming to the remainder of tailportion of the base material. The fish thus assembled on the basematerial are then wrapped in the plastic sheet or placed in the plasticbag, and the packaging from this point is completed as described abovewith reference to Fig. 1. In this form of package, the shrinkage of themeaty parts of the fish caused by the evacuation of the air and by theshrinkage of the sheet material may distort the meaty parts exactly inconformity to the base material and to the contiguous parts of the otherfish so that any space wherein frost may collect in a frozen package iseliminated or minimized to the smallest degree. A small submerged cavitywhich would remain between the fish and the base material and a similarspace in the exposed area along the backs of the fish which would remainwithin a wrapping which was not exhausted and shrunk, are eliminated.

However, in order to avoid excessive exhaustion and eliminate orminimize spaces within the wrapping next to the base material, a basematerial may be provided which will spring inwardly slightly asexhaustion is applied in order to meet the surfaces of the cavity as themeaty material is drawn toward the base material. This is indicated inthe drawings by a slight concavity of the base material shown in across-sectional view. At the edges of the base material slightdistortion is sometimes convenient in order to completely eliminate airpockets without applying excessive exhaustion and shrinkage of the sheetmaterial. However, a relatively undistortable base material can be usedto effect the objects of this invention materially. In general, thewrapping conforms exactly to the contour of the fish and no spaceusually remains. A small slit-like cavity which may be eliminated byextreme evacuation and shrinkage or by careful packaging sometimesappears; but due to its small size and slit-like form, and because it issubmerged, it is relatively unimportant. The wrapped material of anydescription may, and in most cases is finally frozen by methods wellknown.

Meat products thus packaged display not only a shape which simulates anarticle of desired or natural form, but also effectively displays thecolor and other physical characteristics of the material. When a meatproduct, such as a fish, is packaged so as to eliminate air pocketsunderneath the wrapping and without the use of the relativelyundistortable base element, the thin most easily distortable parts ofthe fish, such as the tail fin, are caused to fold or roll in an uncannymanner into an unsightly, displeasing shape which gives the fish a mostundesirable unappetising and unnatural appearance.

The base material may desirably be composed of a relatively stiffcardboard material having a stiffness such as that of Bristol board, butstiffer or more pliant material can be used depending upon the relativepliability of the meat. The base material may be sufficiently pliable toyield somewhat at the edges in order to meet the distorted flesh of thepackaged material, but otherwise the sheet base material should be aself-sustaining material which provides a plane stiffened surface-uponwhich the packaged material is to be-assembled. Thin ordinary woodveneer or plyboard may be cutout in the described manner and many otherplanar or flat materials may be used for this purpose.

From the foregoing disclosure itwill be recognized that the invention issusceptible of modification without departing from the spirit and scopethereof, and it is to be understood that the invention is not restrictedto the specific illustrations thereof which are herein set forth.

I claim:

1. The process of packaging a body of flaccid meat material havingeasily deformable parts which comprises shaping a thin flat relativelydifficultly deformable sheetform base element in a form similar to alongitudinal cross-section of the material to be packaged; said baseelement being provided with shaped parts for supporting and retainingsaid easily deformable parts of said material from edgewise deformationon two sides and from sidewise deformation on only one side; assemblingthe body of meat material on said base element with its said easilydeformable parts laid out on only one side of said shaped parts of thebase element; enclosing the material and base element thus assembled inan envelope of a thin pliable imperforate sheeted wrapping material ofthe kind which shrinks when heated; reducing the pressure of air in saidenclosure; said reduction of pressure being sufficient to collapse thewrapping and cavities within the meat, compress the meat into conformitywith a contacting flat surface of the base member, remove air pocketsbetween said wrapping and said material, and to effect closure ofexternal openings of any erstwhile internal cavities in said materialwhen said Wrapping is shrunk; closing the wrapping to retain saidreduced pressure; and then applying heat to the mate rial at atemperature which is suflicient to shrink the wrapping until it istightly and smoothly drawn around and in contact with all exposedsurfaces of said meat material and the exposed surface and edges of saidbase element.

2. The process in accordance with claim 1 in which the heat is appliedby immersing the wrapped assembly in hot water.

3. The process in accordance with claim 1 in which the base element is astiif element which is not substantially deformed by the reduction ofair pressure and by the shrinkage of the wrapping.

4. The process in accordance with claim 1 in which the base material isrelatively difficult to deform by said exhaustion of air and shrinkageof the Wrapper.

5. The process in accordance with claim 1 in which the base material isrelatively slightly deformable by said exhaustion of air and by saidshrinkage of the wrapper and is deviated from a plane surface at itslateral edges.

6. The process in accordance with claim 1 in which two eviscerated fishare placed back to back on one side of the base material with their tailfins overlapping; said base material being shaped generally in the formof the longitudinal cross-section of a fish, and having a length aboutthat of the fish to be wrapped and a Width not greater than thelongitudinal cross-section of the two fish when assembled back to back.

7. The process in accordance with claim 1 in which an eviscerated fishis placed on one side of the base material; said base material is shapedgenerally in the form of the longitudinal cross-section of saideviscerated fish, and having a length about that of the fish and a widthnot greater than the longitudinal cross-section of the fish to bewrapped; the tail of said fish being spread out flat on the formed tailportion of said base element.

8. The process in accordance with claim 1 in which the base element issmaller than the longitudinal crosssection of the material to be wrappedso that the material to be wrapped will be distorted to meet the edgesof the base element when the wrapping is shrunk.

9. The process in accordance'with claim 1 in which the-wrapped materialis two eviscerated fish assembled on one side of the base material backto back; and said exhaustion andshrinkage of the enclosure formed bywrapping are carried on until the sides of the fish are collapsed anddistorted so as to diminish the internal cavities of the fish and theexternal openings thereto are closed,. until the wrapping materialconforms to the exposed undulations of the assembled fish and theexposed surfaces and edges of the base material, and until air spacesare eliminated between the wrapping material and the fish.

10. The process in accordance with claim 1 in which the material to bewrapped is an eviscerated fish assembled on one side of the basematerial, the shape of which is generally like the cross-section of thefish and is about the length of the fish but narrower than its maximumlongitudinal cross-section; and said exhaustion and shrinkage of theenclosure formed by wrapping are carried on until the cavity within thefish is reduced and the sides of the fish are collapsed thereby formingan external closure to the erstwhile cavity, and until the wrappingmaterial conforms to the exposed undulations of the fish and the exposedsurfaces and edges of the base material, and until air spaces areeliminated between the wrapping material and fish.

11. The process in accordance with claim 1 in which the wrapped materialis finally frozen.

12. The process of packaging an eviscerated fish which comprises placingthe fish on a thin relatively diflicultly deformabte fiat sheet-formbase element with one side of the fish in contact with the base elementand with the tail of the fish spread out upon the base element; saidbase element being at least as broad in its tail por tion as the tail ofsaid fish and about as long as said fish; enclosing said fish and baseelement thus assembled within a thin pliable imperforate sheetedwrapping material which shrinks when heated; reducing the pressure ofair in said enclosure until the wrapping material is collapsed aroundthe exposed surface of the fish and base element and until the airpockets between the said wraping and the exposed surface of said fishare removed, and until the pressure of air in the eviscerated cavity ofsaid fish is reduced and the margins of said cavity are closed; closingsaid wrapping to retain said reduced pressure; and applying heat to thewrapping material until the wrapping is tightly and smoothly shrunkaround said fish and said base element.

13. The process in accordance with claim 12 in which the wrappedmaterial is finally frozen.

14. An article of wrapped meat material comprising a body of relativelyeasily deformable and collapsible meat material, a relatively stiff fiatbase element shaped to conform to the longitudinal cross-section of themeat material to be wrapped and upon which said meat material iscompressed, an evacuated imperforate wrapping of the kind which shrinkswhen heated enclosing said meat material and base element, said wrappingconforming to all the exposed surfaces and edges of said meat materialand to the exposed parts of said base element, and being stretchedtherearound so as to exclude air pockets between the meat material andwrapping and so as to collapse the walls of any internal cavity withinthe meat material and close any external opening thereinto.

15. An article in accordance with claim 14 which is an eviscerated fishmounted on a relatively stiff flat thin member shaped similar to thelongitudinal cross-section of a fish and having a tail portion uponwhich the tail fin of the fish is flattened out and protected fromedgewise deformation by said base element.

16. An article in accordance with claim 14 which comprises twoeviscerated fish assembled on a relatively stiff flat thin member shapedsimilar to the longitudinal crosssection of a fish and having a tailportion upon which the tail fins of the fish are assembled overlappingone another and flattened out on said base member and pro 8 Rosen Oct.31, 1933 Gammeter Feb. 16, 1937 De Poix May 22, 1945 Guyer Jan. 2, 1951Uehlein May 13, 1952 OTHER REFERENCES Modern Packaging," September 1950,pages 93, 94,

1. THE PROCESS OF PACKAGING A BODY OF FLACCID MEAT MATERIAL HAVINGEASILY DEFORMABLE PARTS WHICH COMPRISES SHAPING A THIN FLAT RELATIVELYDIFFICULTY DEFORMABLE SHEETFORM BASE ELEMENT IN A FORM SIMILAR TO ALONGITUDINAL CROSS-SECTION OF THE MATERIAL TO BE PACKAGED; SAID BASEELEMENT BEING PROVIDED WITH SHAPED PARTS FOR SUPPORTING AND RETAININGSAID EASILY DEFORMABLE PARTS SAID MATERIAL FROM EDGEWISE DEFORMATION ONTWO SIDES AND FROM SIDEWISE DEFORMATION ON ONLY ONE SIDE; ASSEMBLING THEBODY OF MEAT MATERIAL ON SAID BASE ELEMENT WITH ITS SAID EASILYDEFORMABLE PARTS LAID OUT ON ONLY ONE SIDE OF SAID SHAPED PARTS OF THEBASE ELEMENT; ENCLOSING THE MATERIAL AND BASE ELEMENT THUS ASSEMBLED INAN ENVELOPE OF A THIN PLIABLE IMPERFORATE SHEETED WRAPPING MATERIAL OFTHE KIND WHICH SHRINKS WHEN HEATED; REDUCING THE PRESSURE OF AIR IN SAIDENCLOSURE: SAID REDUCTION OF PRESSURE BEING SUFFICIENT TO COLLAPSE THEWRAPPING AND CAVITIES WITHIN THE MEAT, COMPRESS THE MEAT INTO CONFORMITYWITH A CONTACTING FLAT SURFACE OF THE BASE MEMBER, REMOVE AIR POCKETSBETWEEN SAID WRAPPING AND SAID MATERIAL, AND TO EFFECT CLOSURE OFEXTERNAL OPENINGS OF ANY ERSTWHILE INTERNAL CAVITIES IN SAID MATERIALWHEN SAID WRAPPING IS SHRUNK; CLOSING THE WRAPPING TO RETAIN SAIDREDUCED PRESSURE; AND THEN APPLYING HEAT TO THE MATERIAL AT ATEMPERATURE WHICH IS SUFFICIENT TO SHRINK THE WRAPPING UNTIL IT ISTIGHTLY AND SMOOTHLY DRAWN AROUND AND IN CONTACT WITH ALL EXPOSEDSURFACES OF SAID MEAT MATERIAL AND THE EXPOSED SURFACE AND EDGES OF SAIDBASE ELEMENT.